REFLECTOR: Hot oil

[Bob Jackson (Jax Tech)]

Scott,

It sounds to me like your WOT fuel flow may be too low.  Ours (custom turbo
IO-550N) is a different engine, I know but our EGTs range from 1375 to 1425
at take-off power (31" MAP and 2700 RPM) with the fuel flow at the standard
IO-550N 29 gph.

Once we get to 1000 AGL and start our sustained climb to altitude (>10 Kft)
we leave the power at WOT, but increase the fuel flow to 34 gph, as is
standard to keep the temps as low as possible during the turbonormalized
climb out, and the EGTs stabilize between a low of ~1150 and a high of ~1300
all the way up.  It's often 95 OAT in Florida, too, and our oil temp's will
reach 210 even 220 by the time we reach 10 Kft, and two of the CHTs will be
around 400 degrees, though most are below 360 degrees -- we're still working
on CHT cooling, especially at altitudes above 10 Kft.

Bob Jackson
Custom turbo IO-550N
N2XF 'heavy'

PS  I forgot to mention that I think a lot of our problem is our weight,
which will typically be 3000 lb single pilot with full (93 gal) fuel --
that's a lotta lard to push up to those high altitudes!

-----Original Message-----
From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
Behalf Of Scott Derrick
Sent: Tuesday, June 28, 2011 6:49 PM
To: Velocity Aircraft Owners and Builders list
Subject: REFLECTOR: Hot oil

I took off from Henderson(Las Vegas) this morning it was 95 degrees. By 
the time I rotated what with taxiing and waiting in line, the engine was 
pretty much hot.

I climbed from 2500 ft to 5,000(clear of the surrounding dirt) and my 
oil temp was 230-240.  My Dynon has an irratting oil temp display that 
rapidly changes temps all the time. A smoothing function is needed o 
that sensor.

Anyway I leveled off and pulled the power back to cool things off. The 
one thing I noticed immediately was the EGT's  were pretty high, high 
1400's.  I would have expected 1200-1300's at full rich. This was the 
first time I've had this new engine at such a low altitude and I think I 
have the (idle) mixture or high pump pressure set to lean.

I eventually gave up on it cooling down, climbed to 8500 and the temps 
started to drop, both egt's and oil temps.

What temps do other big engines +500CI see on hot day climb outs..

Scott